an English mathematician, innkeeper and former Royal Navy gunner who presented the first design for a navigable submarine and wrote important navigational manuals. In 1574, he produced a popular version of the Martín Cortés de Albacar's Arte de Navegar, entitled A Regiment for the Sea. Bourne was critical of some aspects of the original and produced a manual of more practical use to the seaman. He described how to make observations of the sun and stars, using a cross-staff, and how to plot coastal features from the ship by taking bearings using triangulation.
